A few of my tips on 302s and 283s: you build a 283 get head gaskets that fit the bore of the 283 don't get generic over the counter gaskets that fit from 283 to 400 bores, Cross drill and chanfer your crank, if you can afford it Chrome The crank journals ( I can see an argument LOL) I do it But my 302s hit over 8000 rpm! Make sure the machine shop you go to uses torgue plates , for High rpm use shaft rockers or at least a girdle, Dont use aluminum rockers, Be precice on all balancing, Use floating pins, Use only forged pistons, I use solid flat tappet cams (I have my reasons but to each his own) Other guys on here can add more or Ill be typing all day LOL and many may disagree with what I say LOL!